The overall goal during the proposed five year grant period is to develop further the skills and knowledge base of an independent researcher. The research goal of this grant is to develop a comorbidity index for use in arthritis and rehabilitation research. The scope of the proposed grant includes specific elements of research, education and clinical training. Using arthritis as a model for the relationship between a disease and physical functional status, the overall research goal is to define the specific impact of arthritis on the physical function of elders accounting for the simultaneous impacts of comorbidities on function. The specific aims of the research to be undertaken during the initial phase of the grant period are to: 1) conduct a secondary data analysis of data from the Framingham Heart Study to determine the association of radiographically-defined osteoarthritis with specific medical comorbidities and 2) develop an index to account for the combined effects of other comorbidities on physical function in the elderly in arthritis-oriented functional status research. The specific aims of the educational component are to: 1) develop advanced level skill in the statistical manipulation of large data sets for epidemiological study; 2) enhance capacity in the design of clinical trials and longitudinal analyses of function and decline in the elderly; and 3) establish interdisciplinary relationships with colleagues in the Department of Geriatric Medicine and the School of Public Health at Boston University. The specific aims of the clinical training component of this grant are to: 1) obtain enhanced mastery of problems in geriatric clinical medicine and their relationship to interdisciplinary rehabilitation interventions and 2) serve as a teaching resource in physical therapy and rehabilitation to the Departments of Arthritis and Geriatrics. These aims will be accomplished through a program supervised by Boston University Arthritis Section Chief, Dr. Robert F. Meenan, MD, MPH, and conducted under the auspices of the Arthritis Section of the Boston University School of Medicine and its counterpart institution, the Boston University School of Public Health.